<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <script src="../jquery/jquery-3.1.0/jquery-3.1.0.js"></script>
</head>
<body>
<div>1</div>
<div>2</div>
<div>3</div>
<div>4</div>
<script>


    var $obj = $( 'div' );

    var $obj1 = $obj.get(2);
    var $obj2 = $obj.eq(2);

    //first
    var first=$obj.first();
    var last=$obj.last();


</script>
</body>
</html>